I have been pulling my hair out for quite some time to get my Can - bus to USB to see the Vectrix diagnostic software. Well the problem is now understood. (And solved) It seems that Peak have changed the driver for their connector last year. Guess what? The Vectrix software does not work with the new driver. (or at least the version that I have) (thanks to The Laird for all his help in trying to sort this out..)
There is a DLL file to change. The file to change is located in the Vectrix software under ScooterDiag. It is called PCAN_USB.dll.
To resolve the problem you can download the old version of this file from www.peak-system.com. Firstly rename your current PCAN_USB.dll to something else ie old or whatever. Then go to www.peak-system.com click on support, All files from our Product CD (a new window should open), then click on Develop, PC Interfaces, Windows, PCan-light API, Win 32 and then right at the bottom PCAN_USB.dll. Download this file and then place this in the folder where you renamed the file in the earlier instance.
Then it all should work.
Gees - quelle patience! After thinking the problem was a Win 7 issue and going to another older machine - anyway now sorted - it seems this software works fine on Win 7 as well as XP
I hope this can be of use to others.